Impaired Awareness of Hypoglycaemia

Impaired Awareness of Hypoglycaemia

Impaired awareness of hypoglycaemia (IAH) is a reduced ability to perceive the onset of hypoglycaemia while cognition is still intact. It affects 20-25% of patients with type 1 diabetes and about 10% of those with insulin-treated type 2 diabetes.1

IAH arises when repeated episodes of hypoglycaemia raise the glycaemic threshold for symptom generation (i.e. symptoms are only triggered at a lower blood glucose level). Symptoms that would make people aware of impending hypoglycaemia, such as sweating or anxiety, no longer occur above the new threshold. A careful clinical history is often sufficient to identify IAH.2

In addition to significantly increasing the risk of severe hypoglycaemia,3 IAH increases people’s reliance on others to manage their diabetes and can even lead to loss of driving privileges and employment. Scrupulous avoidance of hypoglycaemia can reverse IAH, though this strategy runs the risk of compromising glycaemic control.2